The eta/DSI software has its origins in the automotive CAE community, where the need for efficient finite element modeling tools emerged in the mid to late 1980¡¯s. These tools were needed to address the drive for shortened vehicle development schedules and the desire to implement CAE simulations in the design process.
ETA had been an early innovator in the area of finite element pre & post processing, developing and commercializing the eta/FEMB software in the mid-80¡¯s. This software met the needs of the automotive CAE engineers and was quickly adopted to help the transformation of the automotive CAE community.
As the need for more complex simulations arose, there was a simultaneous increase in low-cost, high-speed computing capacity. This provided the opportunity to create system-level simulations of events, mimicking the test process more accurately. Prior to this time, conventional CAE techniques consisted of smaller, specific analyses tailored to a specific task (such as NVH), separate from the global system-level analysis of the automobile.
The eta/DSI developers were faced with the need for an integrated analysis that included both component-level and full vehicle applications with the ability to perform real-time simulations. The analysis would be dynamic and nonlinear -- unlike the static, linear analysis techniques utilized by the then-current CAE practices.
ETA first tested this concept on simple mechanisms, simulating mechanical systems such as engine/connecting rod/piston/crankshaft systems and suspension mechanisms. The mechanisms were simulated as a dynamic, nonlinear system in real-time events. The results demonstrated that the motion and forces derived from the DSI simulation were the same as the rigid body linkage motion simulation results produced from conventional multibody dynamics software. However, when implementing flexible bodies (FE), the benefit of obtaining realistic stress and strain results of flexible components from the DSI simulation in an event-based fashion produced valuable analysis data that could not be generated in traditional FEA approaches.
ETA engineers moved another step forward by simulating a rotating tire impact in a pothole event. A tire model was developed to include a control volume technique to simulate the tire air pressure behavior under an impact condition. The simulation of the frictional contact of the tire model with the rigid road surface was extremely realistic and correlated with existing tire data.
After years of development and evaluation, it has been confirmed that DSI technology produces repeatable, reliable, and correlated analysis results. The level of confidence from users and correlation results has lead to aggressive simulation use and a broad application scope.